There are so many types of seed that can be planted that one germination date cannot cover all of them. But there is a range for most seed, especially cool season seeds, that we can follow. Most grass seeds planted in the fall will germinate in 5-21 days depending on a few factors. First is the hardness of the seed. The harder the seed coat, the longer it will take to germinate. Second is ground conditions such as soil moisture and organic content. Third is soil and air temperature. And last would be conditions such as seed contact or anything that might prevent it from coming in contact with the soil or being planted. Some seeds such as rye grass are thrown out on top of established grasses such as bermuda. It usually takes a longer period of time for seed to germinate if it has to work its way down to the soil. And oats need to be covered up with soil. If not, they may not germinate at all.